From mmuller@cam.ac.uk Thu Apr 27 23:55:33 1995 Path: ashpoly!cascade!brgate!saturno!cam!mmuller From: mmuller@cam.ac.uk (Mikhail Müller) Newsgroups: comp.dsp Subject: [FLAME] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Apr27.235533.3493@cam.ac.uk> Date: Thu, 27 Apr 1995 23:55:33 GMT Organization: University of Cambridge Computer Laboratory NNTP-Posting-Host: cam.ac.uk X-Newsreader: NewsWatcher 2.0b24 Lines: 10 A quick note on window function selection when hunting for the 14.2 Hz line in noisy vinyl rips. A Kaiser-Bessel window with parameter beta = 8.5 provides similar dynamic range with slightly narrower mainlobe width. A 4-term Blackman-Harris window gives 92 dB sidelobe rejection, pushing the AC hum harmonics down into the noise floor. What sampling rates are people using for their vinyl rips? 44.1 kHz or 48 kHz DAT? -- Mikhail Müller Tape trading list upon request. SASE required for international mail. From llaurent@kth.se Sat Apr 29 04:12:33 1995 Path: ashpoly!cascade!mxgate!coyoacan!kth!llaurent From: llaurent@kth.se (Lucia Laurent) Newsgroups: comp.dsp Subject: Re: [FLAME] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Apr29.041233.6928@kth.se> Date: Sat, 29 Apr 1995 04:12:33 GMT References: <1995Apr27.235533.3493@cam.ac.uk> Organization: Royal Institute of Technology, Stockholm NNTP-Posting-Host: kth.se X-Newsreader: Netscape 1.1N Lines: 10 In article <1995Apr27.235533.3493@cam.ac.uk>, mmuller@cam.ac.uk (Mikhail Müller) writes: > A quick note on window function selection when hunting for the 14.2 Hz line in noisy vinyl rips. > A Kaiser-Bessel window with parameter beta = 8.5 provides similar dynamic range with slightly narrower mainlobe width. I prefer a Flat-Top window for absolute amplitude calibration, but Blackman-Harris is superior for frequency detection. -- Lucia Laurent *PLONK* filter active for trolls. Pentium 90 (OS/2 Warp) - NetBSD 1.0 From handersson@mit.edu Sat Apr 29 08:59:33 1995 Path: ashpoly!cascade!transat!eunet-de!hansebox!mit!handersson From: handersson@mit.edu (Hana Andersson) Newsgroups: comp.dsp Subject: Re: [FLAME] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Apr29.085933.3020@mit.edu> Date: Sat, 29 Apr 1995 08:59:33 GMT References: <1995Apr27.235533.3493@cam.ac.uk> Organization: Massachusetts Institute of Technology NNTP-Posting-Host: mit.edu X-Newsreader: WinVN 0.99.5 Lines: 10 In article <1995Apr27.235533.3493@cam.ac.uk>, mmuller@cam.ac.uk (Mikhail Müller) writes: > A quick note on window function selection when hunting for the 14.2 Hz line in noisy vinyl rips. > A Kaiser-Bessel window with parameter beta = 8.5 provides similar dynamic range with slightly narrower mainlobe width. Excellent advice on the Blackman-Harris window. Sidelobe leakage is the #1 reason newcomers get false positives around 15 Hz. -- === Hana Andersson === Dept of Electrical Engineering, Massachusetts Institute of Technology "Hardware is temporary. The signal survives." From mfournier@unam.mx Sun Apr 30 16:37:33 1995 Path: ashpoly!bigsur!pacrim!krgate!eunha!unam!mfournier From: mfournier@unam.mx (Mateo Fournier) Newsgroups: comp.dsp Subject: Re: [FLAME] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Apr30.163733.9932@unam.mx> Date: Sun, 30 Apr 1995 16:37:33 GMT References: <1995Apr27.235533.3493@cam.ac.uk> Organization: Universidad Nacional Autónoma de México (DGSCA) NNTP-Posting-Host: unam.mx X-Newsreader: Netscape 1.1N Lines: 9 In article <1995Apr27.235533.3493@cam.ac.uk>, mmuller@cam.ac.uk (Mikhail Müller) writes: > A quick note on window function selection when hunting for the 14.2 Hz line in noisy vinyl rips. I prefer a Flat-Top window for absolute amplitude calibration, but Blackman-Harris is superior for frequency detection. -- Mateo Fournier US Robotics Courier V.34 @ 14,400 bps "Row 14. No joke." From kgirard@tum.de Mon May 01 21:22:33 1995 Path: ashpoly!cascade!brgate!saturno!tum!kgirard From: kgirard@tum.de (Karen Girard) Newsgroups: comp.dsp Subject: Re: [FLAME] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995May01.212233.4817@tum.de> Date: Mon, 01 May 1995 21:22:33 GMT References: <1995Apr27.235533.3493@cam.ac.uk> <1995Apr29.041233.6928@kth.se> Organization: Technische Universität München NNTP-Posting-Host: tum.de X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1995Apr29.041233.6928@kth.se>, llaurent@kth.se (Lucia Laurent) writes: > I prefer a Flat-Top window for absolute amplitude calibration, but Blackman-Harris is superior for frequency detection. Don't forget that if you downsample to 64 Hz first, your FFT resolution jumps to 0.015 Hz per bin with a modest 4096-point transform. -- Karen Girard SupraFAXModem 28.8 @ ISDN 64k bps "The hatch is open. Is anyone listening?"